Fuel injector assembly



July 5, 1966 J. v. YOST FUEL INJECTOR ASSEMBLY Filed Oct. 10, 1963 John I/. Yosf INVENTOR.

WWW 5% United States Patent 3,259,379 FUEL INJECTOR ASSEMBLY John V. Yost, 2233 Riverside Drive, Trenton, Mich. Filed Oct. 10, 1963, Ser. No. 315,211 6 Claims. (Cl. 26150) This invention primarily relates to a novel fuel injection system specifically adapted for use with internal combustion engines in modern automobiles.

It is the primary object of this invention to provide a fuel injection system capable of injecting a mixture of air and fuel into an associated combustion engine and maintaining a substantially correct fuel/ air ratio regardless of engine speed, throttle opening or fuel supply pressure.

A more specific object of this invention is to disclose a fuel injector assembly of the character described including a pair of movable means responsive to the amount of air allowed to flow into the intake manifold of the engine for regulating the open-ing of a fuel supply valve which allows fuel to pass through a fuel metering device to mix with the incoming air in correct proportions in said intake manifold. More particularly, one of said means is specifically adapted to operate at idle and low speeds of the engine whereas the other movable means is adapted to function at high speeds of said engine to thus insure the proper fuel/air mixture presented for combustion in the engine.

A further object of this invention resides in the specific design of said first movable means which not only maintains the proper fuel/ air mixture at idle and low speeds but aids in the starting of the engine and if the engine should become flooded when it is started, said means may be used to cut off the fuel supply and open the throttle to clear the engine of fuel when it is cranked.

These together with other objects and advantages which will become subsequently apparent reside in the details of. construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawing forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

The single figure in the drawings illustrates schematically the complete fuel injector assembly comprising the subject matter of the instant invention.

Referring now to the drawing in detail, the fuel injector assembly generally designated by the numeral 10 includes an intake manifold r12 connected to an internal combustion engine. Atmospheric air is adapted to be admitted into said intake manifold through an elongated conduit such as 14 open at one end to the atmosphere and connected to the intake manifold at its other end. Mounted within the conduit 14 is the usual air throttle or valve 16 for restricting or throttling the flow of air through the conduit 14 to the intake manifold 12. A linkage 18 connected to the accelerator of the motor vehicle in which this system is mounted controls the amount of air allowed to flow through the conduit 14 by its connection to the throttle I16 for opening and closing the same. Therefore, it will be understood that at idle and low speeds of the engine the throttle 16 will be in the position substantially as shown in the drawing greatly restricting the flow of the air through the conduit 14 to the intake manifold 12, but when the engine is run at high speeds, the linkage will cause the throttle 16 to pivot from the position shown in the drawing to a position approximately parallel with the axis of the conduit as the accelerator is depressed to move the linkage correspondingly.

The fuel injector assembly 10 also comprises a vertically oriented fuel metering unit 20 connecting a fuel supply line 22 to the intake manifold means through a 3,259,379 Patented July 5, 1966 "Ice fuel line 24. The fuel line 24 includes a fuel divider block 26 branching off into a plurality of fuel supply lines 28 leading to injection nozzles 30 which inject fuel into the intake manifold for mixture with the air admitted to the conduit I14 just prior to combustion in the engine. The fuel metering unit 20 includes a needle valve assembly 32 comprising a needle valve 34 connected to pivotable links 36, 38 and 40 disposed in the fuel metering unit 20. Fuel 42 is adapted to enter the interior of the fuel metering unit 20 through a nozzle 44 connecting the fuel line 22 to the fuel metering unit and which has an orifice 46 cooperating with the needle valve 34 for closing and opening the fuel supply line 22 to the interior of the fuel metering unit. Fuel is adapted to flow through the fuel metering unit 20 and into the fuel line 24 through a connecting element 48 extending from the top of the fuel metering unit 20. A flexible diaphragm 50 closes a portion of the fuel metering unit 20 and is adapted to communicate with the fuel flowing through the fuel metering unit and is sensitive to fluctuations in the fuel pressure in said unit. The diaphragm 50 is also connected to the linkage portion 40 which when pivoted is adapted to move the needle valve 34 to close or open the entrance of the fuel supply line 22 to the flow metering devlce.

The needle valve 34 is not only responsive to changes in fuel pressure within the metering unit 20 but is sensitive to the changes in air flow through the conduit 14 for correlating the amount of fuel admitted to the fuel line 24 through the flow metering unit with the air flowing through the conduit 14 to the intake manifold 12. At idle or low engine speeds, this correlation is accomplished by connecting the accelerator linkage 18 to a cam 52 rotatably mounted upon a bracket 54. This connection includes a driving linkage 56 between the accelerator linkage and the cam. The cam 52 is normally positioned in "abutting contact with the cam follower 58 biased by means of a coil spring 60 into contact with the cam surface of the cam 52. The cam follower 58 connects pivotable lever 62 pivotally mounted upon the bracket 54 to the cam 52. The pivotable lever 62, in turn, is disposed in contact with the linkage portion 40 to thereby transmit pivotab-le movement to the needle valve 34. When starting the engine or running the engine at idle or low speeds, the accelerator will be depressed about halfway which in turn through the linkage 18 will move the air throttle 16 slightly to admit air into the intake manifold 12. When this movement occurs, the accelerator linkage 18, through the driving linkage 56, will rotate the cam 52 a corresponding amount on the rising portion 64 thereof. This will force the cam follower 58 to move to the right as shown in the drawing and pivot the lever 62 in a counterclockwise direction. The lever in turn will move the linkage portion 40 to the right as shown in the drawings to open the needle valve 34 and admit a proportional amount of fuel from the fuel supply line 22 into the flow metering unit 20 thereby causing a proportional amount of fuel to flow through the fuel supply line 24 and into the injector nozzle 30. When the engine is cranked, atmospheric air will move past the throttle 16 in the proportion to the fuel injected through the nozzle 30 for mixture just prior to combustion. If too much fuel is supplied and the engine fails to start, this condition may be remedied by depressing the accelerator completely. This will cause the air throttle 16 to open all the way and will rotate the cam 52 until the cam follower drops from the rising portion 64 of the cam to the depressed portion 66 thereof. This will cause the needle valve 34 to completely shut the entrance of the fuel supply line 22 to the fuel metering device. When the engine is then cranked, it will clear of fuel. Therefore, it should be understood that the fuel injector system just disclosed also prevents flooding of the engine. When the engine is run at low speeds, corresponding up to approximately one-half total throttling opening, the cam 52 will be operative to proportionally increase the entrance of fuel into the flow metering device and the intake manifold by moving the needle valve 34 a corresponding proportional distance to open the orifice 46. When the one-half total throttle opening condition occurs, the cam follower 58 will fall into the depression 66 wherein the needle valve will close the fuel entrance. At this point, a second unit has been provided to take over the maintenance of the proper fuel/ air ratio admitted to the engine.

The latter device includes a turbine wheel 68 rotatably mounted in the conduit 14 above the air throttle 16 between a pair of spaced disks 70 and 72. This is accomplished by mounting the turbine wheel 68 upon a shaft 74 having bearing contacts with the disks 70 and 72. A flexible element such as a string or cord 76 is secured to the turbine wheel shaft 74 and is wound thereabout to form a reeling mechanism with the shaft. The opposite end of the flexible element 76 is connected to the pivotable lever 62.

It will therefore be appreciated that when the throttle is open more than half-way and the cam has been rendered inoperative to pivot the needle valve 34, the air flow through the conduit 14 will develop a sufficient force against the turbine blades of the turbine wheel 68 to tend to rotate the same thus tending to wind the flexible element 76 upon the shaft 74. This in turn will cause the lever 62 to pivot and actuate the linkage portion 40 to open the needle valve 34. As the fuel then flows into the fuel metering unit 20, fuel pressure will be built up upon the flexible diaphragm 50 to develop a force in a direction opposite to the force tending to pivot the lever 62 due to the air flow through the conduit 14. When an equilibrium condition occurs, and the lever 62 is maintained stationary, the fuel/air ratio will be correct for optimum operating conditions of the engine. The air flow through the conduit 14 is then decreased or increased as the case may be due to a change in the running speed of the engine, the lever 62 will open or close the needle valve 34 a proportional amount thereby maintaining the correct fuel/air ratio.

It should also be noted that if the engine speed increases and the throttle 16 opens further, the arm between the connection of the flexible element 76 to the lever 62 and the pivot point for the lever will shorten slightly. This in effect presents a slight enriching tendency of the fuel/air ratio. In order to compensate for the slight variation, a spring 80 is connected between the flexible element 76 and the top of the lever 62.

The fuel injector assembly of the present invention has also solved other problems commonly found in prior devices. In the device disclosed, the fuel metering unit is constructed of a non-heat conducting material, such as plastic to thereby prevent the heat of the engine from conducting through the walls of the metering unit and causing vaporization therein which results in erratic metering. However, some vapor is still formed but it is controlled by causing it to pass through the system by mounting the fuel metering unit with its main axis vertical and placing the outlet of the fuel metering unit at the top so that vapor formed will pass up and out. As already pointed out, the fuel injector assembly disclosed takes into consideration that a rich mixture is necessary for starting the engine and as disclosed this is accomplished by depressing the throttle partway to open the fuel valve and to thereby substantially allow fuel to enter the intake manifold when the engine is cranked. Further, the depression 66 on the cam 52 takes into account the flooding possibilities of the engine and by depressing the accelerator to open the throttle all the way, the fuel supply can be cut off at starting and the engine will clear what fuel has entered the manifold when the engine is cranked.

To summarize the operation of the main parts of the device, it will be realized that when the engine is running at low speed, some air passes by the turbine wheel 68. However, the air movement is too slight for correct metering so that the fuel flow must be controlled by means of the cam 52 and cam follower 58. Therefore, at low speeds, the fuel injector assembly has been designed so that the cam 52 is used to pivot a needle valve 34 to meter fuel flow through the intake manifold. After a high enough speed is reached whereby sufficient air passes by the turbine 6S, the cam mechanism is automatically dispensed with and the turbine wheel 68 will meter the fuel flow through a reel positively connected thereto and to a lever for pivoting the needle valve 34 to proportionally increase and decrease the opening of a fuel supply line to the metering unit 20 and the intake manifold. This occurs when the torque produced by the air passing through the conduit 14 is suflicient to tend to rotate the turbine 68. When the fuel pressure has built up in the fuel metering device 20 so as to prevent further pivotal movement of the lever 62, the fuel/ air ratio is correct, for optimum operation of the engine.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A fuel injector assembly characterized by the maintenance of a substantially correct proportion of fuel injected into an internal combustion engine to air admitted into said engine for mixture with the fuel comprising intake manifold means having an air inlet, conduit means communicating with said air inlet for supplying atmospheric air to said intake manifold means, means disposed in said conduit means for restricting the flow of air to said intake manifold means, linkage means connected to said air restriction means for controlling the amount of air allowed to flow through said conduit means to said intake manifold means by said air restriction means, a fuel supply, fuel metering means connecting said fuel supply to said intake manifold means including valve means for restricting the flow of fuel from said fuel supply to said intake manifold means, and first and second movable means responsive to the positioning of said linkage means and the amount of air allowed to flow through said conduit means to the intake manifold, respectively, for regulating the opening of said valve means, said second movable means responding to a relatively high rate of air flow through said conduit means and said first movable means responding to a positioning of said air flow through said conduit means below said high rate of flow, said first movable valve means including rotatable cam means, pivotable lever means connected to said valve means for opening and closing said valve means upon pivotable movement being imparted thereto, cam follower means connecting said lever means to said cam means responsive to rotation of said cam means for imparting pivotable movement to said lever means, and means driviugly connecting said linkage means to said cam means for rotating said cam means to impart pivotable movement to said lever means through said cam follower means to proportional- *ly increase the opening of said valve means in response to said linkage means allowing an increasing rate of air flow through said conduit means until a predetermined rate of flow is reached, said second movable means including turbine means mounted in said conduit means for rotation by forces developed .by the air flow through said conduit means of a higher value than said predetermined air rate of flow, reel means connecting said lever means to said turbine means responsive to rotation of said turbine means for imparting pivotable movement to said lever means, and flexible diaphragm means communicating with the fuel flowing through said fuel metering means and connected to said valve means for imparting pivotal movement to said lever means in opposition to the pivotal movement imparted thereto by said reel means by transmitting a force developed by the fuel pressure of the fuel flowing through said fuel metering device through the valve means to the lever means, whereby said lever means may proportionally open and close said valve means in response to fluctuations of air flow through said air conduit means.

2. In combination with a combustion engine of the type including an intake manifold, an air and fuel mixing apparatus for providing said intake manifold with a substantially correctly proportioned mixture of air and fuel, said apparatus comprising conduit means including an inlet end and an outlet end communicated with the inlet of said manifold, air valve means disposed in said conduit means operative to control the flow of air therethrough, a fuel supply, fuel discharge means operable to discharge fuel into the air passing through said conduit means downstream of said air valve means, means communicating said fuel supply with said fuel discharge means and including fuel valve means operable to vary the amount of fuel passing from said fuel supply to said fuel discharge means, first control means connected to said air valve means and said fuel valve means for opening and closing said fuel valve means in response to opening and closing said air valve means, second control means connected to said fuel valve means and operative to open and close said fuel valve means in response to an increase and a decrease of flow of air through said conduit means, respectively, said first control means including a lost motion connection with said fuel valve means operable to gradually open said fuel valve means, independently of said second control means, to a partially open position short of its full open position as said air valve is gradually opened to a predetermined position short of its full open position, said second control means including a lost motion connection with said fuel valve means operative independently of said first means, in response to the flow of air through said conduit means exceeding a predetermined minimum air flow generally corresponding to said partially open position of said air valve means during operation of said engine under normal loads, to further open said fuel valve past said partially open position thereof, said apparatus including means, at least during operation of said engine, operative to yieldingly urge said fuel valve means toward its closed position.

3. The combination of claim 2 wherein said first control means includes means, independent of said second control means, operative to allow said fuel valve means to move toward the closed position upon movement of said air valve past said partially open position.

4. The combination of claim 2 wherein said first control means and said fuel valve means include coacting adjustment means operable to adjustably vary the opening of said fuel valve means relative to a predetermined opening of said air valve means.

5. The combination of claim 2 wherein said second control means includes means operative to adjustably vary said predetermined minimum air flow.

6. The combination of claim 2 wherein said second control means is operable to provide a yielding force on said fuel valve means to open the latter past said partially open position thereof in response to an increase in air flow through said conduit means above said predetermined minimum air flow, said means operative to yieldingly urge said fuel valve toward the closed position including means diminishing in effective force in response to a drop in the pressure of the ambient atmosphere.

References Cited by the Examiner UNITED STATES PATENTS 1,547,785 7/1925 Caspar 261-69 2,009,992 8/1935 Beals 26l50 2,344,139 3/1944 Gerson 261-69 2,445,846 7/1948 Barfod et al. 26169 2,591,356 4/1952 Howe 261 X 3,049,111 8/1962 Bogle 261-69 X HARRY B. THORNTON, Primary Examiner.

T. R. MILES, Assistant Examiner. 

2. IN COMBINATION WITH A COMBUSTION ENGINE OF THE TYPE INCLUDING AN INTAKE MANIFOLD, AN AIR AND FUEL MIXING APPARATUS FOR PROVIDING SAID INTAKE MANIFOLD WITH A SUBSTANTIALLY CORRECTLY PROPORTIONAL MIXTURE OF AIR AND FUEL, SAID APPARATUS COMPRISING CONDUIT MEANS INCLUDING AN INLET END AND AN OUTLET END COMMUNICATED WITH THE INLET OF SAID MANIFOLD, AIR VALVE MEANS DISPOSED IN SAID CONDUIT MEANS OPERATIVE TO CONTROL THE FLOW OF AIR THERETHROUGH A FUEL SUPPLY, FUEL DISCHARGE MEANS OPERABLE TO DISCHARGE FUEL INTO THE AIR PASSING THROUGH SAID CONDUIT MEANS DOWNSTREAM OF SAID AIR VALVE MEANS, MEANS COMMUNICATING SAID FUEL SUPPLY WITH SAID FUEL DISCHARGE MEANS AND INCLUDING FUEL VALVE MEANS OPERABLE TO VARY THE AMOUNT OF FUEL PASSING FROM SAID FUEL SUPPLY TO SAID FUEL DISCHARGE MEANS, FIRST CONTROL MEANS CONNECTED TO SAID AIR VALVE MEANS AND SAID FUEL VALVE MEANS FOR OPENING AND CLOSING SAID FUEL VALVE MEANS IN RESPONSE TO OPENING AND CLOSING SAID AIR VALVE MEANS, SECOND CONTROL MEANS CONNECTED TO SAID FUEL VALVE MEANS AND OPERATIVE TO OPEN AND CLOSE SAID FUEL VALVE MEANS IN RESPONSE TO AN INCREASE AND A DECREASE OF FLOW OF AIR THROUGH SAID CONDUIT MEANS, RESPEC- 